Unknown time on the 52nd day of Winter

"Monster cores are inefficient." I said to Schrodinger. "Or at least there is a lot of wasted space."

He had found a mouse when out hunting earlier and brought it back to me. I was sitting on my bedroll drawing up designs for a different kind of core. The problem was that energy was still a limiting factor in a lot of my work. At this point, if I wanted a stronger laser I had two options. Carry around a bunch of smaller cores that I switched out all the time or make a much more powerful core. I was, of course, pursuing both.

Miniaturizing cores was fairly easy but there was an exponential loss of output with size. So, perhaps they would still work for low power applications, once I had all the bugs worked out, but wouldn't be powering weapons. Of course that same exponential curve was only to my benefit as the scale increased. In the body of a human or monster, the limiting factors on size were all about space available in the gut. Hence they were limited to smaller than a ping pong ball, at the largest. But if I were to recreate them outside the body then I would have no such limitations. I could make them as big as I wanted.

Unfortunately it wasn't that simple. For one, my printer spell could only safely be used with my hands completely enclosing the target. I could bind together some parts without fully enclosing them but it was difficult and time consuming. So, if I was to try to make something bigger then I would definitely release harmful radiation. Solution, construct the super core under water. That way the water would absorb the radiation and I could come back to remove any isotopes I made by accident.

"I decided to make a large light magic core." I said. I could hear Schrodinger lapping at the dish of water I had put out for him. "I would probably screw up the magnetic levitation and spinning rings of an earth or water core and have everything blow up in my face."

Though, now that I said that it would be a distinct possibility for any type of core. Schrodinger left his catch for now and padded over to me. He let out a long meow and then turned around to show me his backside.

"Hey, what was that for?" I asked, but he just walked away.

"Ya, I know." I said. "After this we should be done down here."

As much as I was looking forward to getting out of here, I was also dreading my return. What would I say to Mistila? How could I lie to everyone about my magic? I hated lying. The whole past life thing never really came up in conversation but I'm sure if someone in my family had asked about it I would have told them. Maybe that's how I would try and play this too. If I can act like I'm a light mage then then all I will have to do is to not correct people when they make their own assumptions.

I ran through my list of things I needed to be able to do to fake being a light mage.

"Flash spell, check." I said, taking out a baseball sized glass orb with a dark spot at the center. "'Invisible light,' check."

I retrieved a high power infrared laser pointer with a couple of focusing lenses on it to make it narrow to a point about a foot in front of the tip.

"I am getting better at signaling." I said. "I don't actually have to be fully proficient right out of the gate. I just need to know that I can actually speak it and understand it."

I retrieved my safety goggles, in which I had added a Signal transducer to see the infrared and ultraviolet colors. It was just a little color display in the corner of my vision but it was a lot better than holding up the spyglass I had made for long distance signaling.

"Lastly, we have darkness." I said, before letting out a long sigh. I had given up entirely on ranged darkness. I just couldn't figure out how it worked. The ink sack could produce a darkness effect for a time but the channel would wear out eventually and, more critically, people already knew how such items worked and it would be very suspicious to use one if I was really a light mage. I was stuck for a long time before I realized that the color of an object could be affected by its microtexture. After trying, and failing, to reproduce the effect with light magic about a dozen times I remembered a way to accomplish the task through entirely mundane materials science.

I retrieved a rock from my bag that was so black it looked like a hole in the world. It turns out that vertically aligned nanotubes made of graphene, correctly spaced on a surface, make for pretty near total absorption of visible light. The structure was extremely easy to manufacture with my printer spell, permanent unless damaged, and, with a little trial and error, came out with the same eerie loss of texture and shape as the spell. I was proud of what I had been able to accomplish down here. But my time in the cave was coming to an end.

***

Unknown time on the 55th day of Winter

"And this thing is like a monster core?" asked Arin. "It looks like a game ball."

Stolen novel; please report.

She tossed it in the air and caught it with seeming ease.

"Yes, it's like a monster core." I said, rolling my eyes.

She wasn't wrong. It was about the size and shape of a basketball. It was thirty kilograms, warm to the touch, and covered in a layer of aluminum so it was heavy, hot, and shiny but ya, I could imagine some sort of game being played with a ball like this.

"You should paint it." she said.

"Really? What color?" I asked.

She looked at me. Then she looked at Schrodinger.

"Black." she said.

Schrodinger seemed to think this was obvious. I just shrugged.

"Maybe, but what it looks like isn't what matters." I said. "What matters is that this thing generates mana faster than the handheld lasers can use it."

"Wait, faster? Isn't this just a really big monster core?" she asked. "Like, it still takes a few days to recharge itself right?"

I'll admit I felt a bit smug answering.

"Nope." I said. "This one is like a monster core while it's still in the monster. It should recharge its reserves with light mana, from empty to full, in just in a few hours like you do. Well, considering the size of its reserves, it recharges as fast as you would if you were as tall as a building."

Her eyes went wide. She looked back to the ball with more admiration this time. I started to hear a soft shuffling sound in the distance and looked around for Schrodinger. He must have wandered off.

Then Arin got a confused expression.

"Then why do cores make less mana when we die?" She asked.

I wanted to explain it in terms of a car but took a second to think of an example she would have a physical intuition for.

"It's like driving a big cart down a hill." I said. "If you let it, it will fly down the hill, going faster and faster until it crashes. So cores have breaks that will stop the cart if no one is driving. I actually think that the body probably naturally regulates how much mana is being produced. When the body dies the brakes fall into place and the cart slows way down."

She thought about that for a while.

"And you just made yours with what, weaker breaks?" she asked.

"Close, I made the strength of the brakes proportional to the speed of the cart." I said.

As we were talking the shuffling sound just kept getting louder. It started off quiet, so I thought Schrodinger was up to something, but by the time we were talking about carts it was clearly something else. Something bigger. I checked that the laser was in my belt holster. Arin drew her sword and I was again struck by how much she looked like a superhero.

Just then a large form entered the cavern from one of the tunnels. It was another kith, this one easily as big as a full sized truck. I started backing up, immediately looking for ways out.

"Theod, run!" Yelled Arin. Instead of fear, she wore a smirk like she just caught the monster in a trap. The demon said something in a language I didn't know, its voice a cross between a cicada and a garbage disposal.

I couldn't tell if this was one of the ones from the day of my awakening but it sure seemed pissed to see Arin. It rushed forward and I ran. I looked back to see that Arin had ducked its first swipe and rolled past its front legs. I saw a flash and the demon staggered back.

I stopped and looked on in amazement as Arin danced in combat with the kith. She tossed out a globe of light to her left just as she stepped right to avoid being cut. Damn it. What the hell am I doing? She was going to fight this thing and I was going to run? I took out the laser I had made. My hand was trembling as I pointed it at the melee. I was too far away and they were moving too quickly. I ran forward to close the distance while looking for my shot.

"Back up!" I yelled, a bit of panic slipped into my voice.

“Don't worry” she yelled back. “It's too slow to catch me!”

Arin practically flew into a back handspring, disengaging from the monster. She was absolutely crazy. I pushed the big red button. Plasma from a white hot beam scorched a line across its thorax. Instead of cutting through, much of the laser reflected off of the monster's hide to be scattered around the cave.

Then the laser cut off and a second later I was thrown bodily into the cave wall. My shirt was on fire but luckily I landed flat on my face and the fire went out.

"Ouch." I said into the dirt.

My chest was a burning mass of pain. I struggled to look up and saw that Arin had burned through one of its eyes with her laser spell. It was limping on the side where mine had hit it but was clearly not out of the fight yet. Just then, another kith ran into the cave. After just a mark it moved to enter the melee.

Now Arin was on the back foot. She deflected a slice for her neck only to shoot the newcomer in the mouth with a short laser pulse. The black dot from her targeted darkness spell was the only sign of the deadly beam. That gave me an idea. A horribly dangerous idea.

I reached for the light magic core embedded in my handheld laser. I pulled it out and closed my hands around it. Using the adrenaline to focus through the pain I descended into the microscope and started pulling off layers as quickly and safely as I could. It only took a few seconds to start to see the movement of the oxygen and hydrogen below the surface. I opened my eyes and dragged myself to stand. I bolted as fast as I could toward the fight, holding the makeshift bomb as gently as possible. I prayed that this plan wouldn't blow up in my face.

"Hey Ugly!" I yelled.

The newcomer turned around to assess the threat I posed and Arin took the opening to slip her blade in between the exoskeletal plates near its neck. It screamed in pain and struggled to get away. I continued running forward, anticipating what came next. The first monster opened its fang-filled maw wide and lunged to bite off Arin's head from behind. On the run I pulled in my elbow, lined up my shot, and threw the core like a dart straight into the monster's throat. The core triggered its gag reflex and it pulled up short. I caught a rock with my left foot and fell to the ground in a heap. Arin glanced behind her before forcefully yanking her sword out of the monster's neck, half decapitating it in the process.

She turned and held her blade between her and the remaining monster.

"Come on!" I yelled thinking of how fragile that core it just swallowed was. I pulled myself to my feet and took a step toward the kith. "BREAK!"

As if on command the monster's thorax exploded in a shower of gore and viscera that covered Arin and I.

I looked at Arin and saw she was smiling from ear to ear.

"That was awesome!" she said.

Her joy was infectious and I couldn't help but smile back. We were alive. We had survived. Not only that but we had won! Then a wave of exhaustion swept through me. I looked down and saw that my chest was a bloody mess. The demon had cut across it with the back of its red hot scythe blade. The burn was an angry red with a line of seared and bloody flesh through the middle. The pain in my chest swelled and my vision went dim. Arin was saying something but I couldn't make out what it was from so far away. Then everything faded to black and I knew no more.